Department of Rehabilitation Medicine, University of Tsukuba Hospital, Japan

Yukiyo Shimizu

Department of Rehabilitation Medicine, University of Tsukuba Hospital, Japan

Yasushi Hada

Department of Rehabilitation Medicine, University of Tsukuba Hospital, Japan

Hitoshi Shimano

Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba: 1-1-1 Tennodai, Tsukuba, Ibaraki 305-0031, Japan International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Japan Life Science Center of Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Japan Japan Agency for Medical Research and Development-Core Research for Evolutional Science and Technology (AMED-CREST), Japan

[Purpose] The efficacy of a stabilometer-based index of postural stability (IPS) as an indicator of dynamic balance ability was investigated. [Subjects and Methods] Using a stabilometer, we calculated the IPS in 583 healthy subjects (178 males, 405 females) under two conditions (open eyes/hard surface, OE/HS; closed eyes/soft surface, CE/SS). [Results] Results revealed a negative relation between IPS and age. IPS (OE/HS) began to decrease at middle-age (40–60 years old), and then decreased more rapidly during elderly ages (>60 years old). On the other hand, IPS (CE/SS) decreased linearly with increasing age. There was no gender difference between the two IPSs. [Conclusion] These results suggest that IPS can evaluate balance ability quantitatively and without a ceiling effect. It was concluded that IPS (OE/HS) indicates comprehensive balance ability, while IPS (CE/SS) reveals balance ability without compensation by visual acuity and plantar superficial sense.